Journal article
Mapping Spatial Relationships between Residues in the Ligand-Binding Domain of the 5-Ht3 Receptor Using a Molecular Ruler
Biophysical journal, v 98(9), pp 1847-1855
05 May 2010
PMID: 20441748
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
The serotonin 5-HT3 receptor (5-HT3R) is a member of the Cys-loop ligand-gated ion channel family. We used a combination of site-directed mutagenesis, homology modeling, and ligand-docking simulations to analyze antagonist-receptor interactions. Mutation of E236, which is near loop C of the binding site, to aspartate prevents expression of the receptor on the cell surface, and no specific ligand binding can be detected. On the other hand, mutation to glutamine, asparagine, or alanine produces receptors that are expressed on the cell surface, but decreases receptor affinity for the competitive antagonist d-tubocurarine (dTC) 5-35-fold. The results of a double-mutant cycle analysis employing a panel of dTC analogs to identify specific points of interactions between the dTC analogs and E236 are consistent with E236 making a direct physical interaction with the 12 –OH of dTC. dTC is a rigid molecule of known three-dimensional structure. Together with previous studies linking other regions of dTC to specific residues in the binding site, these data allow us to define the relative spatial arrangement of three different residues in the ligand-binding site: R92 (loop D), N128 (loop A), and E236 (near loop C). Molecular modeling employing these distance constraints followed by molecular-dynamics simulations produced a dTC/receptor complex consistent with the experimental data. The use of the rigid ligands as molecular rulers in conjunction with double-mutant cycle analysis provides a means of mapping the relative positions of various residues in the ligand-binding site of any ligand-receptor complex, and thus is a useful tool for delineating the architecture of the binding site.
Metrics
Details
- Title
- Mapping Spatial Relationships between Residues in the Ligand-Binding Domain of the 5-Ht3 Receptor Using a Molecular Ruler
- Creators
- Heather L Nyce - Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PennsylvaniaSpencer T Stober - Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PennsylvaniaCameron F Abrams - Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PennsylvaniaMichael M White - Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania
- Publication Details
- Biophysical journal, v 98(9), pp 1847-1855
- Publisher
- Elsevier
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Pharmacology and Physiology; Chemical and Biological Engineering
- Web of Science ID
- WOS:000277377300018
- Scopus ID
- 2-s2.0-77952283794
- Other Identifier
- 991014877866704721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Biophysics